This invention is based on and claims priority to Japanese Patent Application No. 2000-205617, filed Jul. 6, 2000.
1. Field of the Invention
This invention relates to an engine for a watercraft, and particularly to an improved lubrication system of an engine for a watercraft.
2. Description of the Related Art
Personal watercraft had become popular in recent years. This type of watercraft is quite sporting in nature and carries a rider and possibly one, two, or three passengers. A relatively small hull of the personal watercraft commonly defines a rider""s area above an engine component. An internal combustion engine frequently powers a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The jet propulsion is located within the tunnel and is driven by a driveshaft. The driveshaft usually extends between the engine and the jet propulsion device, through a wall of the hull tunnel.
The rider""s area usually includes an elongated seat that extends along a longitudinal center line of the watercraft. The seat has a bench-like shape that the rider and passengers can straddle. Footwells extend along side the seat. The rider and passengers straddle the seat in a tandem fashion with a rider""s and passengers"" legs positioned on the side of the seat and their feet placed within the foot areas.
Generally, the width of the seat not only provides an ample surface upon which the rider and passengers sit, but also provide space in which to locate an upper portion of the engine, including the engine""s exhaust, induction, and lubrication systems. U.S. Pat. No. 6,155,896 illustrates an exemplary engine arrangement beneath the seat with the overall width of the seat generally matching the overall width of the engine. The cylinder head, cylinder block, exhaust manifold, exhaust expansion chamber, carburetors, and air intake are all located between the sidewalls of the seat and beneath the upper cushion of the seat.
While the position of the riderxe2x80x94with his or her feet positioned wide apart and his or her legs straddling the seatxe2x80x94provides good stability, this stance reduces the ability of the rider to absorb with his or her legs impact forces as the watercraft bounds over wakes. In addition, some small riders with less height find it uncomfortable to sit in a position with their feet widely spaced apart when straddling the seat.
Additionally, two-cycle engines commonly power personal watercraft, as these engines have the advantage of being fairly powerful and relatively light and compact. One particular disadvantage of a two-cycle engine though, is emissions content. Two-cycle engines exhaust large quantities of carbon monoxide and various hydrocarbons. However, when steps are taken to reduce the emissions content of a two-cycle engine, other generally undesirable consequences result, such as an increase in the weight of the engine, cost of manufacture, and reduction of power output.
Thus, four-cycle engines have now been proposed as the power plant for personal watercraft. These engines have the advantage of less hydrocarbon emissions than a two-cycle engine while maintaining a relatively high power output. It is therefore desirable to provide a small watercraft with a four-cycle engine in order to reduce the exhaust emissions without significantly impacting the power output of the engine that powers the watercraft.
While four-cycle engines provide great advantages over two-cycle engines, four-cycle engines are generally more complicated and tend to be larger than two-cycle engines. Thus, the space below the seat and between the sidewalls of the personal watercraft in which the upper portion of the engine is located becomes very crowded. This makes inspection and maintenance of components located toward the lower end of the engine difficult.
One aspect of the present invention involves a watercraft comprising a hull defining an engine compartment, a propulsion device, and a four-cycle internal combustion engine driving the propulsion device. The engine comprises a crankcase member, a crankshaft journaled in the crankcase member, a lubricant filter, a lubricant filter mounting surface, and a catch member. At least a portion of the catch member is located at an elevation below the lubricant filter to collect lubricant dripping out of the filter, the crankcase member or an interface between the filter and the crankcase member. The engine is disposed within the engine compartment such that the lubricant filter is located in a lower section of the engine compartment.
In accordance with another aspect of the present invention, a watercraft comprises a hull defining an engine compartment accessible through an access opening, an internal combustion engine disposed within the engine compartment, and a propulsion device driven by the engine. The engine comprises a crankcase member having a filter mounting surface, a removeably mounted exhaust pipe, a removeably mounted intake box, and a lubrication system having a filter. The filter is mounted to the crankcase member such that when the exhaust pipe and intake box are removed the filter can be accessed through the access opening.
An additional aspect of the present invention involves a watercraft comprising a hull defining an engine compartment accessible through an access opening, an internal combustion engine disposed within the engine compartment, and a propulsion device driven by the engine. The engine comprises a crankcase member having a filter mounting surface, a removeably mountable exhaust pipe, a removeably mountable intake box having an upper portion and a lower portion, and a lubrication system having a filter. The filter is mounted to the crankcase member such that when any of the exhaust pipe, the upper portion of the intake box, or the lower portion of the intake box are removed the filter can be more easily accessed through the access opening.
Another aspect of the present invention involves a method of accessing an oil filter of a four-cycle internal combustion engine of a personal watercraft. The watercraft comprises a hull defining an engine compartment, an access opening to the engine compartment, and a propulsion device. The engine drives the propulsion device. The engine comprises a crankcase member, a crankshaft journaled in the crankcase member, a lubricant filter, a lubricant filter mounting surface, an upper portion of an intake box, a lower portion of the intake box, and an exhaust system. The method also comprises removing any of the upper portion of the intake box, the lower portion of the intake box, and a portion of the exhaust system to increase the clearance between the engine and the access opening.
A further aspect of the present invention involves a watercraft comprising a hull defining an engine compartment, an access opening to the engine compartment, a propulsion device, and a four-cycle internal combustion engine driving the propulsion device. The engine comprises a crankcase member, a crankshaft journaled in the crankcase member, a lubricant filter, a lubricant filter mounting surface, an intake box, and an exhaust system. The lubricant filter extends laterally further from a center plane of the watercraft than a vertical plane including the lateral-most point of the exhaust system and the intake box.
Further aspects, features and advantages of the present invention will become apparent from the following description of the preferred embodiment.